Project Summary/Abstract Significant alcohol and substance abuse disorders and mental health disparities impact American Indian/First Nations (Indigenous) communities, and differential exposure to stressors are etiological factors in these inequities. There is striking evidence that adverse childhood experiences (ACEs; a specific form of stress and trauma) have strong, graded associations with adult behavioral health outcomes and early mortality, but very few Indigenous studies focus on understanding the measurement and impact of ACEs. The overall goals of this Diversity Supplement are to provide Candidate Jessica Elm with opportunities to advance her long-term research career goals of understanding substance use and mental health outcomes as a result of social stressors among Indigenous people and to determine if enculturation ameliorates the impact of ACEs on health. Elm will address a gap in our parent award aims by extending our examination of trajectories of substance use and mental health through early adulthood to include consideration of the etiological contributions of ACEs along with careful evaluation of ACE measurement tools. Through supplemental support, Elm will collaborate with and gain mentorship from our well-established, interdisciplinary community and academic research team and address a critical shortage of American Indian researchers in the health sciences workforce. !